Answer:
C. The chance to be selected into the sample was the same for all veterinarians
Well for the first one,
You have to find out if it is at 25 ft at one second, but since you can't you find the next best thing, find 25 feet then see how many seconds it is at.
For the second one you would have to find where they directly meet, I chose 40 and 20
40 April Sales = 20 March Sales
So this means that for every March sale you would have 2 April sales. 40/20 = 2